Coordinate systems, datums and map projections 1 coordinate systems, datums and map projections 2 every map user and maker should have a basic understanding of projections no matter how much computers seem to have automated the process. This selfpaced, online training teaches the fundamental concepts of map projections, datums, and coordinate systems and demonstrates how to use them using esris arcgis. Coordinate systems, map projections, and geographic datum. Map projections massachusetts institute of technology. Geographic coordinates systems, on the other hand, are expressed in values of longitude and latitude. Map projections have a mapping surface an extrinsic characteristic like cylinder, cone, plane.
Ppt map projections and coordinate systems powerpoint. A gcs is often incorrectly called a datum, but a datum is only one part of a gcs. Ppt coordinate systems, datums and map projections. After an overview of the global positioning system gps, the author introduces the fundamentals of map projections and examines the different types. Map projections and coordinate systems map projections are used to transfer or project geographical coordinates onto a flat surface the easiest way to try to transfer the information onto a flat surface is to convert the geographic coordinates into an x and y coordinate system where x is longitude and y is latitude this is an example of.
After an overview of the global positioning system. A gcs includes an angular unit of measure, a prime meridian, and a datum based on a spheroid a point is referenced by its longitude and. Then you can start reading kindle books on your smartphone, tablet, or computer no kindle device required. Conformal projections retain correct angular relations in transfer from globe to map. Learning the basic properties and uses of coordinate systems understanding the difference between geographic coordinates and projected coordinates getting familiar with different types of map projections managing and troubleshooting coordinate systems of feature classes and images. Done for hundreds of years to create paper maps, it continues, but map projection today is most often really a mathematical procedure done in a. By employing retirement planning software to organize your finances, you are going to have an apparent view of your general financial circumstance. Work undertaken in the usa and ussr on the creation of suitable map projections obtained through numerical analysis has been included. Map projection software free download map projection top. The easiest way to try to transfer the information onto a flat surface is to convert the geographic coordinates into an x and y coordinate system, where x is longitude and y is latitude.
There are many different coordinate systems, based on a variety of geodetic datums, projections, and units in use geographic coordinate systems no projection. Coordinate systems and map projections by maling, d. The appearance, classification and naming of map projections. Conceptual summary of projections aa coo d ate syste sn coordinate systems xy coordinatesderived via projection from latlong t iti 2 dfl t lines of latitude and longituderepresent position on 2d flat map surface spheroid. Find a coordinate system and get position on a map. The first half of the book focuses on datums, exploring different coordinate systems and datums, including two and threedimensional representations of earth coordinates and vertical datums. A projection is the means by which you display the coordinate system and your data on a flat surface, such as a piece of paper or a digital screen. The circle gives the impression that worcester is approximately the same distance from boston as new hampshire, and that the state is nearly five times longer, east to west, as it is. Transform coordinates for position on a map converting latitude longitude degrees coordinates on a map pick gps lat & long or coordinates in a projection system from maptiler team. Projected coordinate systems a map projection is the systematic transformation of locations on the earth latitudelongitude to planar coordinates the basis for this transformation is the geographic coordinate system which references a datum map projections are designed for specific purposes. Coordinate systems and map projections, second edition. The book concludes with a chapter on the abuse and misrepresentation of map. A guide to map projections is an easytonavigate, troubleshooting reference for any gis user with the common problem of data misalignment.
Coordinate systems frameworks used to determine position on the surface of the earth. This book introduces and illustrates what geographic and projected coordinate systems are and the elements that make up each. The revisions take into account the huge advances in geometrical geodesy which have occurred since the early. This is a preparatory homework assignment that follows class coverage of projections and coordinate systems. Map projection means representing a portion of the actual earth on a plane. Enter your mobile number or email address below and well send you a link to download the free kindle app.
Map projection, coordinate system and datum youtube. Thematic mapping using countries and us states as an example, map projections, coordinate systems, data classi. Map projections are introduced on pages 1012, and pages. A gcs includes an angular unit of measure, a prime meridian, and a datum based on a. Map projection and coordinate system free download as powerpoint presentation. Map projection software free download map projection. That new file can be used to define or project other data sets. Introducing coordinate systems and map projections youtube. Some basic ideas about the mathematics of map projections. This lectures a quick overview of what projections and coordinate systems are. Projections and coordinate systems are a complicated topic in gis, but they form the basis for how a gis can store, analyze, and display spatial data.
Spheroid or ellipsoid based systems, local systems. Projected coordinate systems, map projections, parameters, and linear units of measure current as of arcgis version 9. And projected coordinate systems that sacrifice some specificity, but built on top of those geographic coordinate systems, so that we can display and analyze. Students answer a number of questions about coordinate systems, datums, ellipsoids, and projections based on class notes and reading in their textbook.
Map projections displaying the earth on 2 dimensional maps the world from space projection from esri, centered at 72 west and 23 south. Just as all maps have a map scale, all maps have locations, too. A geographic coordinate system gcs uses a threedimensional spherical surface to define locations on the earth. Pdf map projections download full pdf book download. Mar 16, 2015 there are many different coordinate systems, based on a variety of geodetic datums, projections, and units in use geographic coordinate systems no projection. Map projections and coordinate systems before beginning this exercise, read about coordinate systems and map projections at.
Coordinate systems and map projections 2nd edition. State plane coordinate systems are built on map projections. A coordinate reference system crs then defines, with the help of coordinates, how the twodimensional, projected map in your gis is related to real places on the earth. A projected coordinate system pcs is a combination of a map projection, projection parameters, and an underlying gcs that determines the set of x, y coordinates assigned to a map.
When a map projection is used as a basis of coordinate system an origin should be established first. Coordinate systems and map projections sciencedirect. Mar 06, 2020 map projections and coordinate systems map projections are used to transfer or project geographical coordinates onto a flat surface the easiest way to try to transfer the information onto a flat surface is to convert the geographic coordinates into an x and y coordinate system where x is longitude and y is latitude this is an example of. Map projection software free download map projection top 4 download offers free software downloads for windows, mac, ios and android computers and mobile devices. Understanding projections and coordinate systems important knowledge to have, especially if you deal with many different sets of data that come from different sources. European commission joint research centre 2001 eur 20120 en institute for environment and sustainability map projections for europe edited by. Reference surfaces, coordinate systems and projections are the prerequisites for the geospatial analysis of planetary surfaces. Vertical coordinate systems are either gravitybased or ellipsoidal. For instance, in geometry we use x horizontal and y vertical coordinates to define points on a twodimensional plane. A map projection uses mathematical formulas to relate the spherical or ellipsoidal coordinates on the globe to flat, planar coordinates. A tutorial on map projections and geographic coordinate systems. Datums, coordinate systems, coordinate reference systems and.
The shape of the earth and the geodetic datum concept are covered on pages 46. Understanding map projections, datums, and coordinate systems. A coordinate system is a reference system used to represent the locations of geographic features, imagery, and observations, such as global positioning system gps locations, within a common geographic framework. Because degrees of latitude and longitude dont have a standard length, you cant measure distances or areas accurately or display the data easily on a flat map or computer screen. The main difference is that projected, geodetic coordinates are cartesian coordinates with two equally scaled orthogonal. A datum transformation is a method that converts data between two geographic coordinate systems. Working with map projections and coordinate systems in arcgis duration. The map of massachusetts in unprojected decimal degrees of longitude and latitude note the proportion of the lines and the circle. Ppt map projections and coordinate systems powerpoint presentation free to download id. Common geographic coordinate systems are wgs 1984 and nad 1983. Projections and coordinate system linkedin slideshare. Coordinate reference frame a set of control points to realize a coordinate reference system. Projections and coordinate systems may seem complex and arcane to you, but as you become more familiar with gis and gis datasets, you will become more capable of handling different coordinate systems and projections. Completely updated with fullcolor maps and diagrams from arcgis desktop 10.
Coordinate systems and map projections ebook, 1992. Analytical derivation of some map projections including examples of pseudocylindrical and polyconic projections is also covered. From the perspective of a geographic software design three coordinate systems can potentially be addressed. A guide to map projections is an easytonavigate, troubleshooting reference for any gis user with the common problem of data misalignment completely updated with fullcolor maps and diagrams from arcgis desktop 10. In the translation from a spherical surface to a twodimensional, flat surface, a change in the expression of points occurs. Each differ either in the order of the coordinate tuple or in the direction of increasing values. A map projection is a rigorous mathematical means of translating a particular region of our earths curvaceous threedimensional surface into a flat twodimensional representation. We talked about geographic coordinate systems that tie everything back to our spherical model of the earth. A map projection is an integral part of a projected coordinate system which strongly affects your analyses and the look of your data. This book explains in a clear and complete manner the terms and concepts of map projections and how they can be applied to your data.
Scale same in any direction around a point, but scale changes from point to point. Map scale is concerned with reducing geographical features of interest to manageable proportions, coordinate systems help us define the positions of features on the surface of the earth, and map projections are concerned with moving from the threedimensional world to the two dimensions of a flat map or display, all of which are discussed in. Examrace books on mapping, gis, and remote sensing prepares you throughly for a wide range of practical applications. Even though the current list of systems is comprehensive, there may be instances where users may wish to add a brand new coordinate system to meet their particular needs, or perhaps. Over 3500 predefined coordinate systems are readily available for use in most cartographic projects. Spatial datum describes the fixing position and orientation etc. Understanding coordinate management in the geodatabase esri technical paper. Ellipsoidal coordinate systems reference a mathematically derived spheroidal or ellipsoidal volumetric surface.
In the followings we discuss how these parameters are defined and. A datum uses latitude and longitude or geographic coordinate systems to define the locations of points on the surface of a spheroid. Feb 21, 2011 conformal projections retain correct angular relations in transfer from globe to map. Map projection linear distortion is manifested as a difference in distance between a pair of projected map grid coordinates and the true horizontal distance at the surface of the earth. Two basic types of coordinate systems exist for geographic data. Map projections are used to transfer or project geographical coordinates onto a flat surface. We introduce the mapping from a left riemann manifold to a right one specified as conformal, equiaerial and equidistant, perspective and. Projections transformation of curved earth to a flat map. Arcmap map map projectionsdeveloper helplist of arcgis apis lining up data in arcgis, margaret maher esri technical paper. Coordinate systems enable geographic datasets to use common locations for integration. Coordinate systems, projections, and transformations. This approximates the view of the earth from the sun on the winter solstice at noon in cambridge, ma.
Page 79 discuss map scale and the basics of coordinate systems. We introduce the mapping from a left riemann manifold to a right one specified as conformal, equiaerial and equidistant, perspective and geodetic. State plane coordinate system fips, zones and the fifty states, learn all about the spcs. When a map projection is used as a basis of coordinate system an. The main difference is that projected, geodetic coordinates are cartesian coordinates with. Map projections try to portray the surface of the earth or a portion of the earth on a flat piece of paper or computer screen. Gravitybased vertical coordinate systems reference a mean sea level calculation. Large areas tend to look more like they do on the globe than is true for. Map projections download ebook pdf, epub, tuebl, mobi. Projection a process that involves conversion of data from geographic coordinates, lat long to projected coordinates. Download the list of supported geographic and vertical coordinate systems. The course format includes detailed information on how these concepts are applied to different regions of the pacific islands. D h maling a revised and expanded new edition of the definitive english work on map projections.
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